The invention relates to a vehicle braking system comprising regulating devices, which determine the transversely dynamic behaviour of the vehicle, in order to maintain or restore stable vehicle behaviour by setting the braking torque, independently of the driver, on individual vehicle wheels.
In known fashion, modern braking systems are equipped, in addition to the anti-lock braking system (ABS), which prevents the wheels from locking during braking, with regulating devices which actively restore driving stability by braking individual wheels independently of the driver. Thus drive slip regulation avoids wheel slip during driving. Additionally, driving dynamic regulation increases driving safety quite significantly, because the driver is actively supported in transversely dynamic critical situations, in which the rear wheel on the inside of the curve is braked during under-steering, and the front wheel on the outside of the curve is braked during over-steering. For this purpose, to determine the transversely dynamic behaviour of the vehicle, for instance the steering angle which the driver specifies, the transverse acceleration of the vehicle and the yaw behaviour of the vehicle around its vertical axis are captured.
Overturning stability, i.e. the danger of the vehicle overturning laterally when negotiating curves, is a problem. This danger increases with increasing total vehicle height, and occurs, in particular, on road surfaces with a high coefficient of friction. Because the vehicle then reaches the overturning limit before the skid limit, the drive slip regulation and driving dynamic regulation cannot intervene at all, so that a safety-critical driving state exists.